diff mbox

[RFC,v3,5/5] m5mols: Implement .get_frame_desc subdev callback

Message ID 1348674853-24596-6-git-send-email-s.nawrocki@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Sylwester Nawrocki/Kernel \(PLT\) /SRPOL/Staff Engineer/Samsung Electronics Sept. 26, 2012, 3:54 p.m. UTC 
.get_frame_desc can be used by host interface driver to query
properties of captured frames, e.g. required memory buffer size.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/media/i2c/m5mols/m5mols.h         |  9 ++++++
 drivers/media/i2c/m5mols/m5mols_capture.c |  3 ++
 drivers/media/i2c/m5mols/m5mols_core.c    | 47 +++++++++++++++++++++++++++++++
 drivers/media/i2c/m5mols/m5mols_reg.h     |  1 +
 4 files changed, 60 insertions(+)

Comments

Jan Hoogenraad Oct. 6, 2012, 3:24 p.m. UTC | #1 
On my ubuntu 10.4 system

Linux 2.6.32-43-generic-pae #97-Ubuntu SMP Wed Sep 5 16:59:17 UTC 2012
i686 GNU/Linux

this patch breaks compilation of media_build.
The constant SZ_1M is not defined in the includes on my system

Do you know what can be done about this ?

---

/home/jhh/dvb/media_build/v4l/m5mols_core.c: In function
'm5mols_set_frame_desc':
/home/jhh/dvb/media_build/v4l/m5mols_core.c:636: error: 'SZ_1M'
undeclared (first use in this function)
/home/jhh/dvb/media_build/v4l/m5mols_core.c:636: error: (Each undeclared
identifier is reported only once
/home/jhh/dvb/media_build/v4l/m5mols_core.c:636: error: for each
function it appears in.)



Sylwester Nawrocki wrote:
> .get_frame_desc can be used by host interface driver to query
> properties of captured frames, e.g. required memory buffer size.
> 
> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>  drivers/media/i2c/m5mols/m5mols.h         |  9 ++++++
>  drivers/media/i2c/m5mols/m5mols_capture.c |  3 ++
>  drivers/media/i2c/m5mols/m5mols_core.c    | 47 +++++++++++++++++++++++++++++++
>  drivers/media/i2c/m5mols/m5mols_reg.h     |  1 +
>  4 files changed, 60 insertions(+)
> 
> diff --git a/drivers/media/i2c/m5mols/m5mols.h b/drivers/media/i2c/m5mols/m5mols.h
> index 15d3a4f..de3b755 100644
> --- a/drivers/media/i2c/m5mols/m5mols.h
> +++ b/drivers/media/i2c/m5mols/m5mols.h
> @@ -19,6 +19,13 @@
>  #include <media/v4l2-subdev.h>
>  #include "m5mols_reg.h"
>  
> +
> +/* An amount of data transmitted in addition to the value
> + * determined by CAPP_JPEG_SIZE_MAX register.
> + */
> +#define M5MOLS_JPEG_TAGS_SIZE		0x20000
> +#define M5MOLS_MAIN_JPEG_SIZE_MAX	(5 * SZ_1M)
> +
>  extern int m5mols_debug;
>  
>  enum m5mols_restype {
> @@ -67,12 +74,14 @@ struct m5mols_exif {
>  /**
>   * struct m5mols_capture - Structure for the capture capability
>   * @exif: EXIF information
> + * @buf_size: internal JPEG frame buffer size, in bytes
>   * @main: size in bytes of the main image
>   * @thumb: size in bytes of the thumb image, if it was accompanied
>   * @total: total size in bytes of the produced image
>   */
>  struct m5mols_capture {
>  	struct m5mols_exif exif;
> +	unsigned int buf_size;
>  	u32 main;
>  	u32 thumb;
>  	u32 total;
> diff --git a/drivers/media/i2c/m5mols/m5mols_capture.c b/drivers/media/i2c/m5mols/m5mols_capture.c
> index cb243bd..ab34cce 100644
> --- a/drivers/media/i2c/m5mols/m5mols_capture.c
> +++ b/drivers/media/i2c/m5mols/m5mols_capture.c
> @@ -105,6 +105,7 @@ static int m5mols_capture_info(struct m5mols_info *info)
>  
>  int m5mols_start_capture(struct m5mols_info *info)
>  {
> +	unsigned int framesize = info->cap.buf_size - M5MOLS_JPEG_TAGS_SIZE;
>  	struct v4l2_subdev *sd = &info->sd;
>  	int ret;
>  
> @@ -121,6 +122,8 @@ int m5mols_start_capture(struct m5mols_info *info)
>  	if (!ret)
>  		ret = m5mols_write(sd, CAPP_MAIN_IMAGE_SIZE, info->resolution);
>  	if (!ret)
> +		ret = m5mols_write(sd, CAPP_JPEG_SIZE_MAX, framesize);
> +	if (!ret)
>  		ret = m5mols_set_mode(info, REG_CAPTURE);
>  	if (!ret)
>  		/* Wait until a frame is captured to ISP internal memory */
> diff --git a/drivers/media/i2c/m5mols/m5mols_core.c b/drivers/media/i2c/m5mols/m5mols_core.c
> index 933014f..c780689 100644
> --- a/drivers/media/i2c/m5mols/m5mols_core.c
> +++ b/drivers/media/i2c/m5mols/m5mols_core.c
> @@ -599,6 +599,51 @@ static int m5mols_set_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
>  	return ret;
>  }
>  
> +static int m5mols_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
> +				 struct v4l2_mbus_frame_desc *fd)
> +{
> +	struct m5mols_info *info = to_m5mols(sd);
> +
> +	if (pad != 0 || fd == NULL)
> +		return -EINVAL;
> +
> +	mutex_lock(&info->lock);
> +	/*
> +	 * .get_frame_desc is only used for compressed formats,
> +	 * thus we always return the capture frame parameters here.
> +	 */
> +	fd->entry[0].length = info->cap.buf_size;
> +	fd->entry[0].pixelcode = info->ffmt[M5MOLS_RESTYPE_CAPTURE].code;
> +	mutex_unlock(&info->lock);
> +
> +	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
> +	fd->num_entries = 1;
> +
> +	return 0;
> +}
> +
> +static int m5mols_set_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
> +				 struct v4l2_mbus_frame_desc *fd)
> +{
> +	struct m5mols_info *info = to_m5mols(sd);
> +	struct v4l2_mbus_framefmt *mf = &info->ffmt[M5MOLS_RESTYPE_CAPTURE];
> +
> +	if (pad != 0 || fd == NULL)
> +		return -EINVAL;
> +
> +	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
> +	fd->num_entries = 1;
> +	fd->entry[0].length = clamp_t(u32, fd->entry[0].length,
> +				      mf->width * mf->height,
> +				      M5MOLS_MAIN_JPEG_SIZE_MAX);
> +	mutex_lock(&info->lock);
> +	info->cap.buf_size = fd->entry[0].length;
> +	mutex_unlock(&info->lock);
> +
> +	return 0;
> +}
> +
> +
>  static int m5mols_enum_mbus_code(struct v4l2_subdev *sd,
>  				 struct v4l2_subdev_fh *fh,
>  				 struct v4l2_subdev_mbus_code_enum *code)
> @@ -615,6 +660,8 @@ static struct v4l2_subdev_pad_ops m5mols_pad_ops = {
>  	.enum_mbus_code	= m5mols_enum_mbus_code,
>  	.get_fmt	= m5mols_get_fmt,
>  	.set_fmt	= m5mols_set_fmt,
> +	.get_frame_desc	= m5mols_get_frame_desc,
> +	.set_frame_desc	= m5mols_set_frame_desc,
>  };
>  
>  /**
> diff --git a/drivers/media/i2c/m5mols/m5mols_reg.h b/drivers/media/i2c/m5mols/m5mols_reg.h
> index 14d4be7..58d8027 100644
> --- a/drivers/media/i2c/m5mols/m5mols_reg.h
> +++ b/drivers/media/i2c/m5mols/m5mols_reg.h
> @@ -310,6 +310,7 @@
>  #define REG_JPEG		0x10
>  
>  #define CAPP_MAIN_IMAGE_SIZE	I2C_REG(CAT_CAPT_PARM, 0x01, 1)
> +#define CAPP_JPEG_SIZE_MAX	I2C_REG(CAT_CAPT_PARM, 0x0f, 4)
>  #define CAPP_JPEG_RATIO		I2C_REG(CAT_CAPT_PARM, 0x17, 1)
>  
>  #define CAPP_MCC_MODE		I2C_REG(CAT_CAPT_PARM, 0x1d, 1)
>
Laurent Pinchart Oct. 8, 2012, 8:42 p.m. UTC | #2 
Hi,

When did the {get,set}_frame_desc subdev operations reach mainline ? Last I 
knew is that they were an RFC, and they're now suddenly in, without even one 
ack from an embedded v4l developer :-S I'm not totally happy with that.

On Saturday 06 October 2012 17:24:22 Jan Hoogenraad wrote:
> On my ubuntu 10.4 system
> 
> Linux 2.6.32-43-generic-pae #97-Ubuntu SMP Wed Sep 5 16:59:17 UTC 2012
> i686 GNU/Linux
> 
> this patch breaks compilation of media_build.
> The constant SZ_1M is not defined in the includes on my system
> 
> Do you know what can be done about this ?
> 
> ---
> 
> /home/jhh/dvb/media_build/v4l/m5mols_core.c: In function
> 'm5mols_set_frame_desc':
> /home/jhh/dvb/media_build/v4l/m5mols_core.c:636: error: 'SZ_1M'
> undeclared (first use in this function)
> /home/jhh/dvb/media_build/v4l/m5mols_core.c:636: error: (Each undeclared
> identifier is reported only once
> /home/jhh/dvb/media_build/v4l/m5mols_core.c:636: error: for each
> function it appears in.)
> 
> Sylwester Nawrocki wrote:
> > .get_frame_desc can be used by host interface driver to query
> > properties of captured frames, e.g. required memory buffer size.
> > 
> > Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
> > Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> > ---
> > 
> >  drivers/media/i2c/m5mols/m5mols.h         |  9 ++++++
> >  drivers/media/i2c/m5mols/m5mols_capture.c |  3 ++
> >  drivers/media/i2c/m5mols/m5mols_core.c    | 47
> >  +++++++++++++++++++++++++++++++ drivers/media/i2c/m5mols/m5mols_reg.h   
> >   |  1 +
> >  4 files changed, 60 insertions(+)
> > 
> > diff --git a/drivers/media/i2c/m5mols/m5mols.h
> > b/drivers/media/i2c/m5mols/m5mols.h index 15d3a4f..de3b755 100644
> > --- a/drivers/media/i2c/m5mols/m5mols.h
> > +++ b/drivers/media/i2c/m5mols/m5mols.h
> > @@ -19,6 +19,13 @@
> > 
> >  #include <media/v4l2-subdev.h>
> >  #include "m5mols_reg.h"
> > 
> > +
> > +/* An amount of data transmitted in addition to the value
> > + * determined by CAPP_JPEG_SIZE_MAX register.
> > + */
> > +#define M5MOLS_JPEG_TAGS_SIZE		0x20000
> > +#define M5MOLS_MAIN_JPEG_SIZE_MAX	(5 * SZ_1M)
> > +
> > 
> >  extern int m5mols_debug;
> >  
> >  enum m5mols_restype {
> > 
> > @@ -67,12 +74,14 @@ struct m5mols_exif {
> > 
> >  /**
> >  
> >   * struct m5mols_capture - Structure for the capture capability
> >   * @exif: EXIF information
> > 
> > + * @buf_size: internal JPEG frame buffer size, in bytes
> > 
> >   * @main: size in bytes of the main image
> >   * @thumb: size in bytes of the thumb image, if it was accompanied
> >   * @total: total size in bytes of the produced image
> >   */
> >  
> >  struct m5mols_capture {
> >  
> >  	struct m5mols_exif exif;
> > 
> > +	unsigned int buf_size;
> > 
> >  	u32 main;
> >  	u32 thumb;
> >  	u32 total;
> > 
> > diff --git a/drivers/media/i2c/m5mols/m5mols_capture.c
> > b/drivers/media/i2c/m5mols/m5mols_capture.c index cb243bd..ab34cce 100644
> > --- a/drivers/media/i2c/m5mols/m5mols_capture.c
> > +++ b/drivers/media/i2c/m5mols/m5mols_capture.c
> > @@ -105,6 +105,7 @@ static int m5mols_capture_info(struct m5mols_info
> > *info)> 
> >  int m5mols_start_capture(struct m5mols_info *info)
> >  {
> > 
> > +	unsigned int framesize = info->cap.buf_size - M5MOLS_JPEG_TAGS_SIZE;
> > 
> >  	struct v4l2_subdev *sd = &info->sd;
> >  	int ret;
> > 
> > @@ -121,6 +122,8 @@ int m5mols_start_capture(struct m5mols_info *info)
> > 
> >  	if (!ret)
> >  	
> >  		ret = m5mols_write(sd, CAPP_MAIN_IMAGE_SIZE, info->resolution);
> >  	
> >  	if (!ret)
> > 
> > +		ret = m5mols_write(sd, CAPP_JPEG_SIZE_MAX, framesize);
> > +	if (!ret)
> > 
> >  		ret = m5mols_set_mode(info, REG_CAPTURE);
> >  	
> >  	if (!ret)
> >  	
> >  		/* Wait until a frame is captured to ISP internal memory */
> > 
> > diff --git a/drivers/media/i2c/m5mols/m5mols_core.c
> > b/drivers/media/i2c/m5mols/m5mols_core.c index 933014f..c780689 100644
> > --- a/drivers/media/i2c/m5mols/m5mols_core.c
> > +++ b/drivers/media/i2c/m5mols/m5mols_core.c
> > @@ -599,6 +599,51 @@ static int m5mols_set_fmt(struct v4l2_subdev *sd,
> > struct v4l2_subdev_fh *fh,> 
> >  	return ret;
> >  
> >  }
> > 
> > +static int m5mols_get_frame_desc(struct v4l2_subdev *sd, unsigned int
> > pad,
> > +				 struct v4l2_mbus_frame_desc *fd)
> > +{
> > +	struct m5mols_info *info = to_m5mols(sd);
> > +
> > +	if (pad != 0 || fd == NULL)
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&info->lock);
> > +	/*
> > +	 * .get_frame_desc is only used for compressed formats,
> > +	 * thus we always return the capture frame parameters here.
> > +	 */
> > +	fd->entry[0].length = info->cap.buf_size;
> > +	fd->entry[0].pixelcode = info->ffmt[M5MOLS_RESTYPE_CAPTURE].code;
> > +	mutex_unlock(&info->lock);
> > +
> > +	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
> > +	fd->num_entries = 1;
> > +
> > +	return 0;
> > +}
> > +
> > +static int m5mols_set_frame_desc(struct v4l2_subdev *sd, unsigned int
> > pad,
> > +				 struct v4l2_mbus_frame_desc *fd)
> > +{
> > +	struct m5mols_info *info = to_m5mols(sd);
> > +	struct v4l2_mbus_framefmt *mf = &info->ffmt[M5MOLS_RESTYPE_CAPTURE];
> > +
> > +	if (pad != 0 || fd == NULL)
> > +		return -EINVAL;
> > +
> > +	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
> > +	fd->num_entries = 1;
> > +	fd->entry[0].length = clamp_t(u32, fd->entry[0].length,
> > +				      mf->width * mf->height,
> > +				      M5MOLS_MAIN_JPEG_SIZE_MAX);
> > +	mutex_lock(&info->lock);
> > +	info->cap.buf_size = fd->entry[0].length;
> > +	mutex_unlock(&info->lock);
> > +
> > +	return 0;
> > +}
> > +
> > +
> > 
> >  static int m5mols_enum_mbus_code(struct v4l2_subdev *sd,
> >  
> >  				 struct v4l2_subdev_fh *fh,
> >  				 struct v4l2_subdev_mbus_code_enum *code)
> > 
> > @@ -615,6 +660,8 @@ static struct v4l2_subdev_pad_ops m5mols_pad_ops = {
> > 
> >  	.enum_mbus_code	= m5mols_enum_mbus_code,
> >  	.get_fmt	= m5mols_get_fmt,
> >  	.set_fmt	= m5mols_set_fmt,
> > 
> > +	.get_frame_desc	= m5mols_get_frame_desc,
> > +	.set_frame_desc	= m5mols_set_frame_desc,
> > 
> >  };
> >  
> >  /**
> > 
> > diff --git a/drivers/media/i2c/m5mols/m5mols_reg.h
> > b/drivers/media/i2c/m5mols/m5mols_reg.h index 14d4be7..58d8027 100644
> > --- a/drivers/media/i2c/m5mols/m5mols_reg.h
> > +++ b/drivers/media/i2c/m5mols/m5mols_reg.h
> > @@ -310,6 +310,7 @@
> > 
> >  #define REG_JPEG		0x10
> >  
> >  #define CAPP_MAIN_IMAGE_SIZE	I2C_REG(CAT_CAPT_PARM, 0x01, 1)
> > 
> > +#define CAPP_JPEG_SIZE_MAX	I2C_REG(CAT_CAPT_PARM, 0x0f, 4)
> > 
> >  #define CAPP_JPEG_RATIO		I2C_REG(CAT_CAPT_PARM, 0x17, 1)
> >  
> >  #define CAPP_MCC_MODE		I2C_REG(CAT_CAPT_PARM, 0x1d, 1)
Sylwester Nawrocki/Kernel \(PLT\) /SRPOL/Staff Engineer/Samsung Electronics Oct. 9, 2012, 11:38 a.m. UTC | #3 
Hi Laurent

On 10/08/2012 10:42 PM, Laurent Pinchart wrote:
> Hi,
> 
> When did the {get,set}_frame_desc subdev operations reach mainline ? Last I 
> knew is that they were an RFC, and they're now suddenly in, without even one 
> ack from an embedded v4l developer :-S I'm not totally happy with that.

Sorry to hear now you have issues with those patches. I've sent a pull request
on last Wednesday [1], after 3 RFC versions of the whole change set. I've Cced
many people on these patches, including you and Sakari. I have addressed comments 
to some patches you raised and I felt you're generally OK or don't have 
objections (since there was no comments on some patches and I explicitly 
mentioned there I'd like to get them in v3.7). I'm sorry if it was otherwise.

The problem I'm trying to address with those patches have been there for us for
over _one year_ [1], making JPEG capture with s5p-fimc effectively unusable in
the mainline kernel.

We've decided extending struct v4l2_mbus_framefmt was not an option, since it
is exposed to user-space now. Also using controls turned out to not be helpful,
since multiple values need to be passed, where there are multiple logical
streams transmitted by e.g. CSI-2 transmitter in single video frame [2].

It seemed like there is a general agreement on LMML to use the frame 
descriptor callbacks instead. These callbacks are all in-kernel API and can
be changed any time. I'll be happy adapt the drivers to whatever sane changes
are proposed. I've stated in the commit description it's just an preliminary
form. And it at least let's us to move forward and carry on with more serious
problems.

I'll try to do better on letting people know, when sending things upstream
in future.

--

Regards,
Sylwester

[1] http://patchwork.linuxtv.org/patch/14875
[2] https://patchwork.kernel.org/patch/1365451
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diff mbox

Patch

diff --git a/drivers/media/i2c/m5mols/m5mols.h b/drivers/media/i2c/m5mols/m5mols.h
index 15d3a4f..de3b755 100644
--- a/drivers/media/i2c/m5mols/m5mols.h
+++ b/drivers/media/i2c/m5mols/m5mols.h
@@ -19,6 +19,13 @@ 
 #include <media/v4l2-subdev.h>
 #include "m5mols_reg.h"
 
+
+/* An amount of data transmitted in addition to the value
+ * determined by CAPP_JPEG_SIZE_MAX register.
+ */
+#define M5MOLS_JPEG_TAGS_SIZE		0x20000
+#define M5MOLS_MAIN_JPEG_SIZE_MAX	(5 * SZ_1M)
+
 extern int m5mols_debug;
 
 enum m5mols_restype {
@@ -67,12 +74,14 @@  struct m5mols_exif {
 /**
  * struct m5mols_capture - Structure for the capture capability
  * @exif: EXIF information
+ * @buf_size: internal JPEG frame buffer size, in bytes
  * @main: size in bytes of the main image
  * @thumb: size in bytes of the thumb image, if it was accompanied
  * @total: total size in bytes of the produced image
  */
 struct m5mols_capture {
 	struct m5mols_exif exif;
+	unsigned int buf_size;
 	u32 main;
 	u32 thumb;
 	u32 total;
diff --git a/drivers/media/i2c/m5mols/m5mols_capture.c b/drivers/media/i2c/m5mols/m5mols_capture.c
index cb243bd..ab34cce 100644
--- a/drivers/media/i2c/m5mols/m5mols_capture.c
+++ b/drivers/media/i2c/m5mols/m5mols_capture.c
@@ -105,6 +105,7 @@  static int m5mols_capture_info(struct m5mols_info *info)
 
 int m5mols_start_capture(struct m5mols_info *info)
 {
+	unsigned int framesize = info->cap.buf_size - M5MOLS_JPEG_TAGS_SIZE;
 	struct v4l2_subdev *sd = &info->sd;
 	int ret;
 
@@ -121,6 +122,8 @@  int m5mols_start_capture(struct m5mols_info *info)
 	if (!ret)
 		ret = m5mols_write(sd, CAPP_MAIN_IMAGE_SIZE, info->resolution);
 	if (!ret)
+		ret = m5mols_write(sd, CAPP_JPEG_SIZE_MAX, framesize);
+	if (!ret)
 		ret = m5mols_set_mode(info, REG_CAPTURE);
 	if (!ret)
 		/* Wait until a frame is captured to ISP internal memory */
diff --git a/drivers/media/i2c/m5mols/m5mols_core.c b/drivers/media/i2c/m5mols/m5mols_core.c
index 933014f..c780689 100644
--- a/drivers/media/i2c/m5mols/m5mols_core.c
+++ b/drivers/media/i2c/m5mols/m5mols_core.c
@@ -599,6 +599,51 @@  static int m5mols_set_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
 	return ret;
 }
 
+static int m5mols_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				 struct v4l2_mbus_frame_desc *fd)
+{
+	struct m5mols_info *info = to_m5mols(sd);
+
+	if (pad != 0 || fd == NULL)
+		return -EINVAL;
+
+	mutex_lock(&info->lock);
+	/*
+	 * .get_frame_desc is only used for compressed formats,
+	 * thus we always return the capture frame parameters here.
+	 */
+	fd->entry[0].length = info->cap.buf_size;
+	fd->entry[0].pixelcode = info->ffmt[M5MOLS_RESTYPE_CAPTURE].code;
+	mutex_unlock(&info->lock);
+
+	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
+	fd->num_entries = 1;
+
+	return 0;
+}
+
+static int m5mols_set_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				 struct v4l2_mbus_frame_desc *fd)
+{
+	struct m5mols_info *info = to_m5mols(sd);
+	struct v4l2_mbus_framefmt *mf = &info->ffmt[M5MOLS_RESTYPE_CAPTURE];
+
+	if (pad != 0 || fd == NULL)
+		return -EINVAL;
+
+	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
+	fd->num_entries = 1;
+	fd->entry[0].length = clamp_t(u32, fd->entry[0].length,
+				      mf->width * mf->height,
+				      M5MOLS_MAIN_JPEG_SIZE_MAX);
+	mutex_lock(&info->lock);
+	info->cap.buf_size = fd->entry[0].length;
+	mutex_unlock(&info->lock);
+
+	return 0;
+}
+
+
 static int m5mols_enum_mbus_code(struct v4l2_subdev *sd,
 				 struct v4l2_subdev_fh *fh,
 				 struct v4l2_subdev_mbus_code_enum *code)
@@ -615,6 +660,8 @@  static struct v4l2_subdev_pad_ops m5mols_pad_ops = {
 	.enum_mbus_code	= m5mols_enum_mbus_code,
 	.get_fmt	= m5mols_get_fmt,
 	.set_fmt	= m5mols_set_fmt,
+	.get_frame_desc	= m5mols_get_frame_desc,
+	.set_frame_desc	= m5mols_set_frame_desc,
 };
 
 /**
diff --git a/drivers/media/i2c/m5mols/m5mols_reg.h b/drivers/media/i2c/m5mols/m5mols_reg.h
index 14d4be7..58d8027 100644
--- a/drivers/media/i2c/m5mols/m5mols_reg.h
+++ b/drivers/media/i2c/m5mols/m5mols_reg.h
@@ -310,6 +310,7 @@ 
 #define REG_JPEG		0x10
 
 #define CAPP_MAIN_IMAGE_SIZE	I2C_REG(CAT_CAPT_PARM, 0x01, 1)
+#define CAPP_JPEG_SIZE_MAX	I2C_REG(CAT_CAPT_PARM, 0x0f, 4)
 #define CAPP_JPEG_RATIO		I2C_REG(CAT_CAPT_PARM, 0x17, 1)
 
 #define CAPP_MCC_MODE		I2C_REG(CAT_CAPT_PARM, 0x1d, 1)